Cooling means for turbines



July 15, 1952 F. P. SOLLINGER COOLING MEANS FOR TURBINES 3 Sheets-Sheet1 Filed Sept. 11, 1946 N TOR INVE FERDINAND F SDLLINEER.

AT T CIRNEY IIIIIJA IIIII n 0 n m 3 m m? n w w "4 m July 1952 F. P.SOLLINGER coouuc MEANS FOR TURBINES 3 Sheets-Sheet .2

Filed Sept. 11, 1946 R. NEER.

L N W R m m Patented July 15, 1952 COOLING MEANS FOR TURBINES FerdinandP. Sollinger, Paterson, N. assignor to Curtiss -Wright 7 of DelawareCorporation, a corporation Application September 11, 1946, S'erial'No.696,287

I This invention relates to turbines and is particularly directed to theconstruction of the turbine'rotor .to provide for the flow of a coolingfluid in heat exchange relation therewith.

- A conventional form of turbine rotor comprises a rotor :disc portionhaving a cylindrical outer rimfrom which the turbineblades projectradially, these blades beingsubjected to the heat of the hot workingfluid of the turbine. Turbines, particularlygasturbines, are designedfor operation at extremely high temperatures of the working' fluid formaximum turbine efficiency. If the high temperature of the turbineworkingzzfluidis transmitted to the disc and hub ofithe turbine rotor,thesafe operating stress of .theiturbine rotor is materially reduced.Accordingly, one of the problemsencountered in the design and operationofga turbine is the provision of means foradequatelycooling the turbinerotor. 1 v

An object of 'thisinventionis; the provision of novel means. permittingthe flow of cooling air in heat exchange relation with the rim of theturbine wheel. Specifically, the invention comprises a pair ofshelf-like spaced flanges projecting from a turbine blade shank, theseflanges cooperatingwith similar flanges on the shanks of the adjacentturbine blades to provide passagesbetween the shanks of each bladecommunicating with opposite ends of the turbine rotor. In addition,means are provided for circulating cooling air through these passages tocool the the shank of the turbine blades thereby reducing the amountofheat conducted tothe web ofthe turbine rotor. The radially outerflangeof said spaced flanges cooperates with the cor responding flanges on theadjacent blades to form a continuous cylindrical surface forming theradially inner boundary of the turbine working fluid,,the workingportions of the turbine blades. projecting radially outwardly from thissurface. J

A further object of this invention is the provisionof anovel flangeconstruction on each blade of ,a, multi-stage turbine. rotor whereby theflanges on the blades of one stage cooperate with the flanges on theblades of the adjacent stage to provide a continuous cylindrical surfaceforming the radially inner boundary oi the turbine working fluid. Astill further object of this invention comprises a turbine blade flangeconstruction on a multi-stage turbine rotor whereby the flanges on theblades of each stage cooperate with the flanges on the blades of anadjacent stage to provide passages establishing communi- 7 Claims. v(01. 25a-39.15)

2 cation between the remote ends of the multistage rotor through which acooling fluid may flow. 7

Other objects of this invention will become .apparent upon reading theannexed detailed along lines 2-2, 33, 4-4 and 5-5 respectively of Figure1;

Figures 6 and 7 are perspective views of the firststage turbine bladeslooking in downstream and upstream directions respectively;

-Eig ure 8' is a perspective view of the second stage turbine blades asviewed in an upstream direction;

Figure 9 is a side view partly in section of a modified turbine blade;and

Figures 10, 11 and 12 are sectional views taken along lines Ill-l0, H-lland l2l2 respectively of Figure 9.

Referring first to Figure 1 to 8, a two-stage turbine rotor indicatedatIt! comprises a pair of rotor members l2 and I4, each drivably connected to a shaft; [6. The radially outer portions of the discs of therotor members 12 and I4 are secured together by bolts 18 projectingthrough the rotor members and suitable bosses formed thereon. Blades 20are welded to the outer rim ofthe turbine rotor "member l2 as indicatedat 22 and blades 24 are welded to the outer rim of the turbine rotormember [4 as indicated at 26. As illustrated in Figures 2 and 3 there isone blade '24 for each blade 20. The blades 20 comprise the first stageof the turbine rotor and the blades24 comprise the second stage of theturbine rotor. Instead of welding the blades tothe turbinerotor, theymay be secured thereto by any othersuitable means. Fixed blades 28project radially inwardly between the first stage blades 20 and thesecond stage blades 24 from the turbine housing structure 29. i

The turbine motive fluid is suitably directed into the blades 20 from acombustion chamber 3] by an annular nozzle construction 30 having fixedblades32. After leaving the first stage blades 20,'the turbine motivefluid is directed by the fixed blades 28 into the second stage blades24... From the second stage blades, the turbine motive fluid dischargesinto the exhaust duct '34. The relative'disposition of the rotaryblades20 and 24 and stationary blades 28' is best seen'in Figure .2.This fl'gure also discloses. by suitable 3 arrows, the approximatedirection of the entrance and exit velocity of the working fluidrelative to the blades 28 and 24 respectively and the direction ofrotation of these blades.

Each blade 28 is provided with a flange or shelf-like construction 36having a substantially rhomboid shape. The shank of each blade 28 isprovided with a second flange or shelf-like construction 36 radiallyspaced from said first flange and also having a substantially rhomboidshape. Each flange 36 terminates adjacent to the corresponding flangesof the adjacent blades 28 to form a substantially continuous outercylindrical surface from which the working pottion of the blades 28project. Similarly, each flange 38 terminates in substantially abuttingrelation with the corresponding flanges of the I adjacent blades 28whereby the flanges 36 and 36 provide passages 48 between the shanks ofadjacent blades.

Each blade 24 is also provided with a pair of shelf-like flanges 42 and44 having a spacing similar to the spacing of the flanges 36 and 38.Each flange 42 and 44 terminates adjacent to V the corresponding flangesof the adjacent blades 24. Thus, the flanges 42 form a substantiallycontinuous cylindrical surface from which the working portions of theblades 24 project. In

. addition, the flanges 42 of the second stage blades 24 form a smoothcontinuation of the flanges 36 of the first stage blades 28. Asillustrated; the flanges 36 and 42 abut approximately midway of thefixed blades 28. In this way, the flanges 36 and form a substantiallycontinuous inner boundary for the turbine working fluid from one end tothe other of the multi-stage turbine rotor I8. Similarly, the flanges 44terminate adjacent the corresponding flanges of the adjacent blades 24whereby the flanges 42 and 44'provide passages 46 between the shanks ofthe blades 24. 'Also,- the flanges 44 of the second stage blades 24 forma continuation of the flanges 38 of the first stage blades 28 so as toaline the passages 48 and 46 thereby providingcontinuous closedpassages48, 46 through the multi-stage rotor 18: The passages 48, '46 extendbetween the shanks of the rotor blades 28 and 24 from one end of themulti-stagerotor 18 to the other and each of these passages iscompletely closed by the tur bine blade flanges and the adjacent bladeshanks. Also, there is one such passage 48, 46 on each side of each pairof turbine rotor'blades 28 and 24. i

The passages 48, 46 permit the flow of cooling air therethrough, therebycooling the turbine rotor blade shanks and reducing the heat conductedto the web of theturbine rotor. To facilitate the flow of' air throughthe passages 48, 46, the upstream end of the turbine rotor member i2 isprovided with a centrifugal im peller communicating'with the passages48, 46. For this purpose, a shroud 46 is secured to the rotor by thebolts l8 and conventional centrifugal blower or impeller blades 58 areformed rigid therewith. As illustrated, these blades 58 and the shroud48 extend radially outwardly to the entrance of the passages 48, 46.

ing air is forced through the blade shank passages 48, 46 bythe'iinpeller 58 and from these passages the cooling air discharges intothe ex- With this arrangement, during turbine operation, cool- 4 flanges36 and 38 that this portion of the blade shank has substantially thesame general outline as the radially inner end of the working portion ofthe blades 28. With this construction, the centrifugal forces acting onthe working portions of the blades 20 are transmitted radially inwardlyto the turbine rotor 12 without inducing bending, stresses in theflanges 36 and 36. That'is, the shank 'of' the blades 28 between theflanges 36 and 38 is formed so as not to undercut any substantialportion of the inner end of the working portion of the blades 28. Inthis way, substantially each point on the blades 28 has a radiallystraight metallic connection through the shank of each blade with therim on the'turbine rotor I2. Accordingly, the flanges 36 and 38 do nottransmit the centrifugal forces acting on the working portions of theblands 28 to the blade shanks and to the turbine rotor. As best seen inFigures 3 and 7, the shank of each blade 28 is extended downstreambetween its spaced flanges 36 and 38 by a web construction 51 hollowedout on its inner side to reduce its weight. As illustrated, each blade28 also has recessed portions 52 and 54 radially inward of the flanges38 for decreasing the Weight of the blades. 'The recess portions 52 and54 for the blades 28 also do not undercut the working portions of theseblades.

The shank of each blade 24 is formed. gen= erally similar to the shankof the blades 28. That is, the shank of each-blade 24 radially inward ofits working portion and between its flanges 42 and 44 follows thegeneral outline of the inner end of the working portion of the blade 24.The shank of each blade 24 is extended upstream between its flanges 42and 44 by a web construction 55 similar to the web 5| of the blades 28.In addition, as illustrated the shank extension 5| of each blade 28abuts the corresponding extension 55 of a blade 24. whereby said shankextensions separate each passage 48, 46 from its corresponding adjacentpassages.

The cooling air leaving the passages 48, 46 discharges into an annulardiffuser passage 56. This annular difiuserrpassag'e is provided withdiffuser vanes 58 to reduce'the rotationalvelocity of the; cooling airas it leaves turbine rotor 48, 46 thereby straightening out this flowbefore it discharges into the exhaust duct 34. Also,- the eflectivecross sectional areaof the discharge end of the diffuser passage 56' isdesigned so that the cooling air discharges into the exhaust duct 34with substantially the same-velocity as the ad jacent velocity of theturbine exhaust fluid inthe duct 34.

With the aforedescribed' construction, the. spaced shelf-like flanges onthe shanks of the fixed blades 28. In ges andturbine rotor ouspassage-walls from urb'ine motive fluid e rotor. os'e a two-stageturymwardiy of the space him rotor, the invention is not so limited butmay of stages of, rotating blades.

1 Figures 9 to, 12 disclose a modified blade construction for a singlestage turbine, each blade 60 being secured to the rim of a turbine rotor62, for example, by welding, as indicated at 64, or by any othersuitable construction. Each blade 60 has a pair of radially spacedflanges 66 and 68 which terminate adjacent. to corresponding flanges ofthe adjacent bladegBfl. Thearrangement is such thatthe facing walls ofthe flanges 66 and 68, and the adjacent blade shanksform the walls ofpassages extending through the turbine rotor between the shanks of theblade 60. With this construction, a suitable cooling fluid can be causedto, ,flow through these passages between the shanks of the turbineblades, e. g. by means of a blower as illustrated in Figure l.

The passages between the shanks of the turbine blades may be made quiteirregular by providingribs or baiiies In, H and 12 on one side of theblade shank and. abutting ribs or baffles '14, 15 and 16 on the adjacentblade shank. Except for baffle 12, these baffies only extend radiallypart way across the passages between the blade shanks so that thecooling fluid, in flowing through these passages, must follow theirregular paths around the baiiles as indicated in Figure 9, therebyinsuring intimate contact of the cooling fluid with the shanks of theblades 60. Obviously, if desired, similar baffies may be provided in thestructure of Figures 1-8.

While I have described my invention in detail in its present preferredembodiment, it will be obvious to those skilled in the art, afterunderstanding my invention, that various changes and modifications maybe made therein without departing from the spirit or scope thereof. Iaim in the appended claims to cover all such modifications. I

I claim as my invention:

1. A turbine comprising a multi-stage turbine rotor having a first and asecond stage of turbine blades secured thereto about its periphery, theblades of each stage being circumferentially spaced about said peripheryand being axially spaced from the blades of the other stage, fixedturbine blades disposed between said first and second stage turbinerotor blades, and a shelf-like flange projecting laterally from theshanks of each of said turbine rotor blades, each said flange extendingcircumferentially into substantially abutting relation with the adjacentblades of its stage of turbine rotor blades and extending in a generallyaxial direction into substantially abutting relation with the flanges ofsaid other stage of turbine rotor blades to form the inner boundary ofthe turbine motive fluid path between said blades and to form passagesinwardly thereof between the shanks of adjacent circumferentially spacedturbine rotor blades'for the flow of a cooling medium through saidpassages.

2. In combination, a multi-stage turbine rotor having a first and asecond stage of turbine blades secured thereto about its periphery, theblades of each stage being circumferentially spaced about said peripheryand being axially spaced from the blades of the other stage, fixedturbine blades disposed between said first and second stage turbinerotor blades, a shelf-like flange projecting laterally from the shanksof each of said turbine rotor blades, each said flange extendingcircumferentially into substantially abutting relation with the adjacentblades of its stage of turbine rotor blades andextendingin a generallyaxial direction into substantially abutting relation with the flanges ofsaid other stage of turbine rotor blades to form the inner boundary ofthe turbine motive fluid path between said blades, said flanges beingarranged to form passages inwardly thereof between the shanks ofadjacent circumferentially spaced turbine rotor blades, and means forcausing a cooling medium to flow, through said passages. l

1 3'. In combination, a multi-stage turbine rotor having a first and asecond stage of turbine blades secured thereto about its periphery, theblades of each stage being circumferentially spaced about said peripheryand being axially spaced from the blades of the other stage, fixedturbine blades disflanges being arranged to form passages inwardlythereof between the shanks of adjacent circumferentially spaced turbinerotor blades, meanslfor causing a cooling medium to flow through saidblade shank passages, passage means establishing communication betweensaid blade shank passages and said exhaust duct, said passage meanshaving side walls inclined to the rotor axis to at least partiallystraighten out the w of the cooling medium before said medium dischargesinto said exhaust duct. '1 l 4. A- turbine comprisingga multi-stageturbine rotor having a first and a second stage of turbine bladessecured thereto aboutits periphery, the blades of each stage beingcircumferentially spaced about said periphery and being axially spacedfrom the blades of the other stage, fixed turbine blades disposedbetween said first and second stage turbine blades, a pair of radiallyspaced flanges projecting laterally from the shank of each of saidturbine rotor blades, each pair of said flanges projectingcircumferentially into substantially abutting relation with thecorresponding flanges of the adjacent turbine rotor blades of its stageand projecting generally axially into substantially abutting relationwith the corresponding flanges of the turbine rotor blades of the otherstage, said flanges and the shanks of said turbine rotor blades formingthe walls of passages through said multi-stage rotor between the shanksof adjacent circumferentially spaced turbine rotor blades for the flowof a cooling medium through said passages.

5. A turbine comprising a multi-stage turbine rotor having a first and asecond stage of turbine generally axially into substantially abuttingre- 'to the other between the shanks of adjacent cir-- cumferentiallyspaced turbine rotor blades for the flow of a cooling medium throughsaid passages.

6. A turbine comprising a multi-stage turbine rotor having afirst and asecond stage of turbine blades secured thereto about its periphery, the

blades of each stage being circumferentially spaced about said peripheryand being axially spaced from the blades of the other stage, fixedturbine blades disposed between said first and second'stage turbineblades, a pair of radially spaced flanges projecting laterally fromtheshank of each of said turbine rotor blades, each pair of said flangesprojecting circumferentially into substantially abutting relation withthe corresponding flanges of the adjacent turbine rotor bladeslof itsstage, said pairsof flanges and the blade shank portions therebetweenprojecting generally axially into substantially abutting relation withthe shanks and corresponding flanges of the turbine rotor blades of theother stage, said flanges and the shanks of said turbine rotor bladesforming the walls of individual passages extending through saidmulti-stage rotor from one end to the other between the shanks ofadjacent circumferentially spaced turbine rotor 8 turbine bladesdisposed between said first and second stage turbine blades, 9, pair orradially spaced flanges projecting laterally from the shank of each ofsaid turbine rotor blades, each pair of said flanges projectingcircumferentially into substantially abutting relation with thecorresponding flanges of the adjacent turbine rotor blades, the shank ofeach turbine rotor blade be- 1 tween its said flanges being formed so asnot to undercut any substantial portion of the working portion of itsblade for the flow of a cooling medium through said passages.

'7. A turbine comprising a multi-stage turbine rotor having a first anda secondstage of turbine blades secured thereto about its periphery, theblades of each stage being circumferentially spaced about said peripheryand being axially spaced from-the blades of the other stage, fixedblades of its stage, said pairs of flanges and the blade shank portions'therebetween projecting generally axially into substantially abuttingrelation with the shanks and corresponding flanges of the turbine rotorblades of the other stage, said flanges and the shanks of said turbinerotor blades forming the walls of individual passages extending throughsaid multi-stage' rotor from one end to the other between the shanks ofadjacent circumferentially spaced turbine rotor blades, the portion ofthe shank of each turbine rotor blade between its said flanges radiallyinwardly of the working portion of its blade havinga profile generallythe same as the profile'of the radially inner end of said workingportion for the now of a cooling medium through said passages.

FERDINAND P. SOLLINGER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,061,648 Westinghouse May 13,1913 1,544,318 Hodgkinson June 30, 192% 1,708,402 Schilling Apr. 9, 19292,213,940 Jendrassik 1 Sept. 3, 19% 2,243,467 Jendrassik May 27, 19412,401,826 Halford June 11, 1946 2,407,531 Birmann Sept. 10, 1946 FOREIGNPATENTS Number Country Date- 665,762 Germany Oct. 3, 1938

